Overcasting sewing machine



OVERCAS'TING SEWING MACHINE Filed Oct. 2, 1943 5 Sheets-Sheet 3 ANTHONYSARDU INVENTOR ATTORNEY 0a. 15, 1946. A, SARDU 2,409,592

OVERCASTING SEWING MACHINE Filed Oct. 2; 194a 5 Shets-Sheet 4 ANTHONYSAR DU INVENTOR ATTORNEY bct.1 5',1946. v A.'SARDU' OVERCASTING SEWINGMACHINE! FiledOt. 2, 1945 L 5 Sheets-Sheet s ANTHONY sARou NVENTORATTQRNEY Patented Oct. 15, 1946 UNITED STATES PATENT OFFICE OVERCASTINGSEWING MACHINE Anthony Sardu, Brooklyn, N. Y.

Application October 2, 1943, Serial No. 504,787 1 Claim. (01. 112-172)This invention relates to an overcast sewin machine having a needle inthe form of a single circular arc and which passes completely throughthe fabric being stitched.

An object of this invention is to provide improved means for positivelyholding and driving the needle, the said means comprising a plurality ofcavities of circular cross-section in one side of the needle andspring-pressed pins slidably mounted in a rotatable disk or head andadap to enter said cavities for gripping and rotating said needle.

Another object of this invention is to provide a needle shaft having thesaid head at one end thereof, and a housing enclosing the head. The headhas a circular groove of a depth adapted to receive the needle toapproximately one-half of its thickness. A cover has a circular groovefor receiving the other half of the needle; means is also provided forsecuring the cover and housing to the frame of the sewing machine in amanner as to cause concentric alinement of the grooves and forsupporting the needle in concentric relation with the needle shaft forrotation thereby.

Another object of this invention is to provide a needle-plate positionedin parallel relation with the needle shaft. and havin a tongueprojecting therefrom and to remove a portion of'the housing to permitthe tongue to be positioned inwardly of the housing, clear of the pathof the needle, and the needle to pass around the tongue.

Another object of this invention is to provide a housing cover having acut-out portion in alinement with the cut-out portion in the housing andto provide a needle plate positioned in a horizontal plane and adaptedfor supporting fabric in position for the needle to pass through an edgethereof, the cut-out portion of said cover forming a guide for thefabric.

Another object of this invention is to provide cam means positionedinside said housing and adapted to release said pins successively fromsaid needle prior to the approach of its sharp pointed end to the needleplate to permit successive portions of said needle to pass through saidfabric while being rotated.

Another object of this, invention is to provide four-motion feedingmeans in coacting relation with said needle actuating mechanism to causesimultaneous overcast stitching and feeding.

With the above and other objects in view, the invention 'will behereinafter more particularly described, and the combination andarrangement of parts will be shown in the accompanying drawof thehousingH has a circular portion 2|.

ings and pointed out in the claim which forms' part of thisspecification.

Reference will nowbe had to the drawings, wherein like numerals ofreference designate corresponding parts throughout the several views, inwhich:

Figure 1 is a side elevation of the sewing machine, partly broken awayto show the interior thereof.

Figure 2 is an end view showing the front portion of the sewing machineshown in Figure 1.

Figure 3 is a cross-sectional view, the section being taken as on line3-3 in Figure 8.

Figure 4 is a front elevation of the needle.

Figure 5 is a fragmentary perspective view showing a schematic cam andneedle-gripping pin arrangement.

7 Figure 6 is a fragmentary top plan view of the cam and needle grippingpins.

Figure '7 is a front view of the housing and head or carrier for theneedle-gripping pins.

Figure 8 is a front view of the housing and threading door, on anenlarged scale.

Figure 9 is a plan view of the cloth and needle plates, and a stitchedfabric strip.

Figure 10 is a plan view of four-motion actuating mechanism for thefeed-dogs.

Figure 11 is a side elevation of the feedin mechanism shown in Figure10.

Figure 12 is a fragmentary cross-sectional View of the mechanism shownin Figures 10 and 11, the section being taken as on line I2-I2 in Figure11.

In the illustrated embodiment of the invention, the numeral It]indicates a sewing machine comprising a fixed hollow box-like frame I Iha= ing a main drive-shaft I2 mounted in the lower portion thereof, thedrive-shaft I2 having a gear I3 secured thereon.

An idler shaft I4 is rotatably mounted in the frame I I above the shaftI2 and carries a gear I5 which is in intermeshing relation with the gearA needle shaft I6 is rotatably mounted in a housing H at the front endof the frame I I. The needle shaft I6 is in right-angular relation withthe idler shaft I4.

A bevel gear I8 secured to the idler shaft I4 is in intermeshingrelation with a bevel gear I9 secured to the needle shaft I6. Thehousing I! is secured to the frame I I by screws 2!). One end A coverEZhaving a circular portion 23 of the same periphery as the circularportion 2| of the housing I! is secured to the housing I! by screws 24.

As shown on an enlarged scale in Figure 3,

the arcuate needle 25 is rotatably mounted in a circular groove 26 in adisk-shaped enlargement 2'! at one end of the needle shaft IS. Thediskshaped enlargement 2! is enclosed by the hollow circular portion 2|of the housing ll. It will be noted that the needle 25 is also rotatablymounted in a circular groove 28 in the circular portion 23 of the cover22.

It is to be noted that the needle 25 has cavities 33 positionedcrosswise of the needle and that shoulder pins 3| having pointed ends 32slidably mounted in the disk-shaped portion 21 of the needle shaft it,are resiliently pressed by coil springs 33 into the cavities 3B and intoengagement with the needle 25.

For the purpose of this invention, the shoulder pins 3| must be releasedsuccessively from engagement with the needle 25 prior to the approach ofthe sharp pointed end 28 of the needle to a cloth plate 43 having ahorizontally positioned work supporting surface. I provide an arcuatecam Ill fixed to the end. wall 4 .2 of the housing ll. The cam 41 has asharp end 43 which successively engages-collar-shaped outer ends 38' ofthe pins 31' and pulls the pins in a direction parallel with the shaft[6.

Each shoulder pin and spring 33 is mounted inside an aperture 3 3 in thedisk-shaped portion 27 of the needle shaft it. I provide apertured disks35, Figure 6, which are suitably mounted in the reduced end portions 36of the pins 3!. Rivets 3'! hold the disks 35 fixed to the outer surfaceof the disk-shaped. portion 27. In the assembled position shown inFigure 6, the diskshapedouter end 38' of the shoulder pin 3! is inspaced relation from the vertical. face 44 of the disk-shaped portion 2?a distance suificient to cause disengagement of the pins- 31, one at atime, from the needle 25, prior to the approach of the needle cavities-3B; 36, to the cloth plate or work supporting base 46.

It is to be noted that the spaced relation of the collar-shaped outerends 38 of the shoulder pins M from the rear face 44 of the disk-shapedportion 2.?- is such. as to permit each collar 38 to engage the sharp.end 43 of the stationary cam l. When the collar (53 reaches themid-portion of the cam, the pin St is pulled out of engagement with theneedle. During the time the collar remains in contact with the cam, thepin remains out of engagement with the needle; The moment the collarpasses the cam, the pin is instantly forced back into engagement withthe needle by the spring 33.

In the embodiment of the device shown in Figures 4 to '7 inclusive, theneedle 25 used therewith has two cavities 30 for engagement with twopins 3|. Under practical conditions where heavy material is to bepenetrated by th needle, three cavities 3G and three pins 31 may beemployed so as to provide two pins in engagement with the needle whileon pin is out of engagement.

As shown in Figure 8, the annular cover 23 on the housing I! (Figure 3)has a threading door d5 pivotally mounted on a pin 46 secured in ears4'! integral with the housing cover 22. The door 4-5 has a threadingaperture 48 therethrough. The aperture 48 is positioned in the axis ofrotation of the needle 25 to permit a thread passing through theaperture into the opening within theannular cover 23 to follow theneedle during its rotation.

It is to be noted that the needle thread is at the central portion ofthe axis of the orbit of the needle and that an end of the thread isthreaded positioned in parallel relation and extend from the front tothe rear of the machine. The feed bar 53' adjoins an end face of theframe ll.

At the rear; each feed bar is bifurcated to provide rectangularopenings, the opening in the bar 53 being numbered 55 and the opening inthe bar 55 being numbered 56. The openings 55 and 56 receive in slidingengagement a rectangular block 51', which is rockably mounted upon a pin58.1ixed in the frame I I.

At the front, each feed bar is bifurcated to provide rectangularopenings, the opening in the bar 53 being numbered 60 and the opening inthe bar 54' being numbered GI. The openings 68 andtl receive in slidingengagement a rectangular block 62 which is mounted on an eccentricportion 63 of the shaft l2 and is vertically movable to lift thefeed-dogs.

At the end adjacent the eccentric portion 63, the main shaft [2 has areduced stem 55 which is concentric with said shaft. Upon the concentricstem 85 there are mounted two eccentrics 66 and 67 keyed to the stem bya key 68.

The eccentrics 66' and 6'! impart horizontal motions to the feed-bars 53and 54, motion being transmitted through a link connection 69 betweenthe eccentric 63 and the feed-bar 54, and a link connection '2'!) at oneside of the link 69, between the eccentric 57 and the feed-bar 53. Theforward ends of the links 69 and ill encircle their respectiveeccentrics S5 and 61, and at the rear ends are pivotally secured totheir respective feedbars by bolts H and 12 which extend from thefeed-bars parallel with the shaft 2.

The bolts H and i2 serve to clamp sleeves T3. '54 against the feedbars.The sleeves form pivotal supports for the rear ends of the links 68, It.The link 78 has an elongated opening through which the bolt 12 andsleeve i4 pass without interfering with the movements of the link 6'9.

In operation, the eccentrics 6S and ii! impart horizontal motions to thefeed-dogs 5!, 52'. The eccentrically actuated block 52 effects verticalmovements to the feed-dogs.

Two cooperating four-motion feeding means are thus provided, each ofwhich may operate in all its movements independently of the other. Bygiving the rear feed-dog 52 a greater amount of horizontal movement astretching of the fabric may be eifected. By giving the forward feed-dog5| a greater amount of horizontal movement a gathering of the fabric maybe effected. The feed-dog 5| operates in advance of the needle 25 andthe feed-dog 52 operates in the rear of the needle.

A presser-foot 80 is carried by a presser-bar 8 l whichisslidablysupported in the sewing machine head 82.

In operation, a thread 83 is passed between thread tension discs 84 andthen through the threading aperture 48 in the threading door 45. Thethread then enters an aperture 85 in the needle 25, then passes througha concealed arcuate groove 86 in the interior of the needle and finallyemerges through an aperture 81 near the pointed end 29 of the needle.

Upon rotation of the pulley 89 the needle 25 is rotated. The needlecarries the thread 83 through an edge portion of fabric 99 lyinghorizontally upon the cloth plate 40. The needle then passes round atongue 11 in the needle plate 18. Repeated actuation of the sewingmachine causes the feed-dogs 5| and 52 to impart a feeding movement tothe fabric for every stitch and, as best shown in Figure 9, there isformed a continuous row of overcast stitching 9| along an edge of thefabric 90.

As shown in dotted lines in Figure 2, the upper portion of thepresser-bar 8| has a reduced portion 92 which carries a coil spring 93.The upper end of the spring is housed in a cavity in the lower portionof a tubular threaded member 94. The lower portion of the spring 93rests upon an enlarged lower portion of the presser-bar Bl. The threadedmember 94 may be adjusted to cause the presser-foot 80 to bear upon thefabric lying upon the cloth plate 40 with a desired feeding pressure. Alifting lever 95 is slidably mounted at the rear of the head 82 andcarries a screw 96 by means of which the lever is secured to thepresser-bar 8 l. The operator raises the lever, and presser-bar, andpresser-foot to permit the manipulation of the fabric lying between thepresser-foot and the needle plate 18.

As shown in Figure 1, this machine comprises a controllable lubricatingsystem 91 shown in my Patent No. 2,202,817. This system comprises wicks98 lying in an oil reservoir 99 and extending to parts to be lubricated,such as the gears l3, I5 and bearing for the shaft 14, etc. An oil drainvalve I90, disclosed in my said patent, maintains a predetermined oilpressure inthe oil reservoir. An oil storage chamber I] and a pump (notshown) serve to provide a constant circulation of oil during operationof the sewing machine.

As shown in Figure 2, the lower portion of the head 82 is broken away toshow the presser bar 8| having a key I02 which is slidably mounted in aslot I03 in a bushing I04. The slot I03 terminates in a circular cavityI05 above the slot. The operator may thus raise the foot 80 so that thekey I92 enters the cavity 195, when it is possible to swing thepresser-foot 89 towards the rear or to the left of the machine toprovide a clear space in front of the threading door 45.

As shown in Figure 9, it will be seen that the stitching 9| is straighton the top of the fabric, while the stitching below the fabric isinclined. It is to be noted that when it is desired to make inclinedstitching on the top or normally exposed surface of the fabric, that thesaid surface is placed up side down on the cloth plate 40. It is thuspossible to stitch straight stitching or inclined stitching as desiredon any surface of the cloth.

In accordance with the patent statutes I have described and illustratedthe preferred embodiment of my invention, but it will be understood thatvarious changes and modifications can be made therein without departingfrom the spirit of the invention as defined by the appended claim.

I claim:

In a sewing machin having a stationary frame, a needle shaft, ahorizontally positioned work supporting base fixed to said frame and inline with the axis of said needle shaft, a rotatable needle in the formof a semi-circular arc and having a threading passageway in a portion ofits arcuate body, and an opening at each end of said passageway,permitting passage of a thread through said passageway, means forcausing rotation of said needle, a needle plate positioned parallel withsaid needle shaft and having a tongue projecting therefrom, said needlebeing movable between said tongue and the body of said needle plate,said needle plate being adapted to support fabric thereon in ahorizontal position, resiliently contacting thread tension disks mountedabove said work supporting base, a stationary threading door mounted onsaid frame in spaced relation from said needle and in parallel relationwith the plane of rotation of said needle, said door having a threadingaperture in alinement with the axis of said needle, said axially alineddoor aperture permitting a continuous supply of thread to be fed to saidneedle in a conical orbit during rotation of said needle.

ANTHONY SARDU.

